The overall objective is to obtain a validated theoretical method to predict the distribution of the ventilation, perfusion, stress, and strain in the lung, and the ventilation/perfusion mismatch in health, disease, and trauma. Because of the aim on theory, the mathematical approach and computer simulation is emphasized. Because of the emphasis on validation, comparison between theoretical predictions and experimental results in stressed. Three topics are selected for concentrated study in the next period: 1) Mathematical approach to respiratory system integration, 2) Pulmonary circulation in the dog, 3) Dynamics of the lung under impact loading. The general theory will be based on the principles of continuum mechanics, with as few ad hoc hypothesis as possible. For pulmonary circulation studies, the objective is to relate the flow with morphometric, rheologic and physical variables such as the pressures in the pulmonary arteries, veins, airways, and pleura; the branching pattern of the arteries, veins, and capillaries; and their dimensions and elasticity. Verification of the theory has been done by experiments on cat. This will be extended to dog. The required basic morphometric and rheological data will be collected. For the dynamics of the lung when it is subjected to a shock loading, we will clarify the wave propagation, reflection, refraction, and focusing in the lung, and the trauma due to impact by gas overpressure in bomb explosion, blunt impact by automobile crashes, or in high speed deployment of airbag protection device. The basic mechanism of lung injury, especially with respect to edema and hemorrhage, will be studied.